SAN DIEGO, California (CNN) -- As thousands flee the wildfires ravaging seven Southern California counties Tuesday, others are scrambling to help the throngs of people displaced and injured by the blazes.

Since the weekend, wildfires have destroyed more than 1,000 homes in a path of destruction more than 100 miles long, ranging from north of Los Angeles to southeast of San Diego. In all, an estimated 425 square miles have been scorched.

Hundreds of thousands of people were seeking refuge in crammed shelters, schools and stadiums, and the number was expected to climb as residents were evacuated in and around the path of the wind-fueled wildfires.